fix(ui): items-per-page input handling only on blur DataTable

[luannmoreira]

Description

This PR improves the behavior of the items-per-page combobox in the DataTable component by:

• Adding reactive state tracking for the menu's open/close state.
• Deferring input sanitization until the menu closes, instead of on every blur or keypress.
• Avoiding unnecessary pagination resets when the entered value hasn’t changed.

Motivation

Previously, the input would trigger sanitizeItemsPerPage() and reset to page 1 on any blur, even if the value hadn’t changed. This was disruptive to the user experience when interacting with the dropdown.

• This update ensures:
  • Sanitization happens only once, after the menu closes.
  • Pagination is reset only when the value actually changes.

Changes

• Bound v-model:menu to track combobox open state.
• Added @update:menu to handle menu close and trigger validation.
• Introduced itemsPerPageMenuOpen ref.
• Updated logic to prevent redundant calls to goToFirstPage().

Testing

• Manually tested:

  • Selecting preset values from the dropdown.
  • Entering custom numeric values.
  • Leaving the input blank or entering invalid input.
  • Verifying page reset only occurs on value change.